HTTP Status Code Lookup

The HTTP Status Code Lookup explains what a status code means and what usually goes with it, covering the whole 1xx through 5xx range. The first digit tells you the broad outcome: informational, success, redirect, client error, or server error, and the specific code narrows it down. It is especially useful when a response you did not expect shows up and you need to know whether it is your fault or the server, and when a 429 or a 503 tells you to back off. The tool looks up the meaning of a code you enter and does not make network requests itself. HTTP status codes are grouped by their first digit, and that grouping is the fastest way to place a response before looking up the exact meaning. Codes beginning with one are informational, two mean success, three indicate a redirect that the client should follow, four mean the request itself was a problem, and five mean the server failed while handling an otherwise valid request. Within a group the differences matter. A redirect can be permanent or temporary, which determines whether a client should update a stored address, and the last modification variants exist to support conditional requests. Client errors separate authentication from authorisation and distinguish a missing resource from a method that is not allowed, each pointing at a different fix. Server errors cover everything from an unhandled exception to a dependency that is down, and the rate limiting and unavailable codes carry the additional meaning that the client should wait and retry rather than retry immediately. Knowing what a code implies about who is responsible is often more useful than the wording of the code name.

📘 Related guide: Read an HTTP status code and pick the fix →